/**
 * Array
 *
 * @author 徐长乐
 * @date 2019/10/21
 */
public class Array<E> {
    private E[] data;
    private int size;

    public Array(int capacity){
        data = (E[])new Object[capacity];
        size = 0;
    }
    public Array(){
        this(10);
    }
    public  int getSize(){
        return size;
    }
    public int getCapacity(){
        return data.length;
    }
    public boolean isEmpty(){
        return size == 0;
    }
    public void addLast(E e){
        add(size,e);
    }
    public void  addFirst(E e){
        add(0,e);
    }
    public void add(int index,E e){
        if (size==data.length)
            throw  new IllegalArgumentException("Add failed .Array is full.");
        if (index < 0 || index > size)
            throw  new IllegalArgumentException("Add failed .Require index >= 0 and index <= size.");
        if (size == data.length)
            resize(2*data.length);
            for (int i =size - 1;i >= index;i--)
             data[i+1]=data[i];
            data[index] = e;
            size ++;
    }

    private void resize(int newCapacity) {
        E[] newdata= (E[])new Object[newCapacity];
        for (int i = 0; i < size ; i++)
            newdata[i]=data[i];
            data=newdata;
    }

    public E get(int index){
        if (index < 0 || index >= size)
            throw  new IllegalArgumentException("Get failed.  index is Illegal");
        return data[index];
    }
   public void set(int index , E e){
        if (index < 0 || index >= size)
            throw  new IllegalArgumentException("Get failed.  index is Illegal");
        data[index] = e;
    }
    public boolean contains(E e){
        for (int i = 0; i < size ; i ++){
            if (data[i].equals(e))
                return true;
        }
        return false;
    }
    public  int find(E e){
        for (int i = 0; i < size ; i ++) {
            if (data[i].equals(e))
                return i;
        }
        return -1;
    }
    public E remove(int index){
        if (index < 0 || index >= size)
            throw  new IllegalArgumentException("Get failed.  index is Illegal");
        E ret = data[index];
        for (int i = index + 1 ;i < size ; i ++)
            data[i-1] = data[i];
        size --;
        data[size] = null;
        if (size == data.length / 2)
            resize(data.length / 2);
        return  ret;
    }
    public  E  removeFirst(){
      return   remove(0);
    }
    public  E removeLast(){
        return remove(size-1);
    }
    public  void removeElement(E e){
        int index = find(e);
        if (index != -1)
        remove(index);
    }
    @Override
    public String toString(){
        StringBuilder res= new StringBuilder();
        res.append(String.format("Array:size = %d ,capacity = %d\n",size,data.length));
        res.append('[');
        for(int i = 0 ; i < size ; i ++){
            res.append(data[i]);
            if ( i != size -1)
                res.append(", ");
        }
        res.append(']');
        return res.toString();
    }
}
